It may be the messenger service that pops up. If it's still happening try blocking ports 135,137, 138 (UDP) and 135, 139, 445 (TCP). I think there's another higher up as well.

You can also disable it by doing this.

1. Go to Start, then Run and type in services.msc Click Ok
2. Scroll to Messenger, select it, right click it and choose Properties.
3. Under startup choose "Disabled", then choose Stop.
4. When stopped, click Ok.

My brother had this. We eventually killed the process by elimination. If the ad-busting programs don't get it then I'll find the name of the process (it was "win<something>". I'll get in touch with my brother and see if he can remember the name of it. A sneaky bugger it was.

remember that not all popups are evil, imagine photo galerys etc. i seen a site where the menu was in a popup once.
greets

Click to expand...

While that is true, the phrase "Pop Ups" is taken to refer to advertisments/undesirables. Website features although technically 'popping up' aren't covered by this expression.

In all fairness, features such as the one you describe will cease soon. With pop up blocking now a standard feature in both the quality browsers - and coming soon to IE as well - most webdesigners wont bother with the hassle of having to instruct people to add their site to the whitelist and will adopt for conventional navigation methods. In fairness, with CSS toys to play with, there's a lot of scope for "fancy" navigation without having to mess with popup windows.